TV show - lighter and hyperbaric chamber explosion

[MrVegas]

OK - I watched an episode of Midsomer Murders yesterday. At the end, the murderer, rather than go to prison, goes into a hyperbaric chamber -- I believe the show indicated 100% oxygen and twice normal atmospheric pressure. He lights a cigarette lighter and everyone goes running. There is a massive explosion blowing out the entire bottom floor of a pretty good-sized building.

Would that actually happen? Obviously, I understand there is a huge risk of a massive flash fire inside the chamber, but would the chamber itself explode in spectacular fashion? This was a surprisingly difficult question to resolve online. There were a few news stories (some discussed on Scubaboard) indicating that there had been deadly explosions, but other reading indicated that the fire was in most cases confined to the inside of the chamber.

Just wondering if I can believe what I saw on TV in this instance.

 

[broncobowsher]

You should get something about like this

 

[Akimbo]

There is a massive explosion blowing out the entire bottom floor of a pretty good-sized building.

Possible but improbable. Yes, steam boiler (pressure vessel) explosions have destroyed multi-story buildings and ships but all chamber fires have been contained. However, none that I know of have been pressurized with pure Oxygen.

There isn't that much fuel in a typical chamber, aside from the humans. The explosive force, which is just very rapid combustion, is dependent on the fuel. The guy in the chamber would be a crispy critter for sure.

 

[Akimbo]

At the end, the murderer, rather than go to prison, goes into a hyperbaric chamber

Another unrealistic factor is multi-place (person) chambers are not piped so they can be pressurized with pure O2. Single place HBOT (Hyperbaric Oxygen Treatment) chambers are but multi-place chambers are pressurized with air and Oxygen supplies for BIBS (Built-In Breathing System) mask are very small, like ¼" or 6mm.

Realism isn't taken too seriously in the entertainment industry. Plastic explosives supposedly with Semtex and C4 are always accompanied by giant fireballs and charred wreckage.

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[MrVegas]

Realism isn't taken too seriously in the entertainment industry. Plastic explosives supposedly with Semtex and C4 are always accompanied by giant fireballs and charred wreckage.

Thanks for the video -- fun stuff! In the TV show, the hyperbaric chamber was in a sports facility for a rugby team (which also had a cryotherapy chamber, which was also the scene of a nasty death). Of course, before he blew himself up in the hyperbaric chamber, the murderer did let everyone outside know that he had disabled all of the controls so that it was impossible to depressurize the chamber from the outside or open the door. That struck me as unlikely -- he also didn't have any trouble with his ears as the chamber pressurized.

 

[vjb.knife1]

I agree with everything Akimbo said. When I was in Commercial Diving school in the early 1970's, the school purchased a lock on bell Hyperbaric chamber, or maybe it was donated, from a large commercial diving company. It had a fire in it because they had been using hydrogen in their trimix and gotten the PP of the H and O to the percentage that lit it up. We sandblasted, painted and refitted it and had it tested and it passed. It was compatible with a bell / PTC that we already owned so it was used as a trainer for Saturation diving. So even though it had a fire inside at some pressure it did not explode and did not overstress the pressure vessel.

 

[vjb.knife1]

Realism isn't taken too seriously in the entertainment industry. Plastic explosives supposedly with Semtex and C4 are always accompanied by giant fireballs and charred wreckage.

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I went to an U/W explosives school with a compnay called Brower located in the desert way east of Los Angeles in the early 1970's. We shot off a lot of different types of high explosives from dynamine to multipart liquids. I have told people many times that there is no big fireball because they burn but at a rate 5 miles a second or more. Most either don't believe me or don't understand. And, of course, when you detonate something like that underwater you do not want to be close enough to see it.

 

[NickHH]

Unlikely to be an explosion, very likely to be a fire.

Another TV show (Hannibal, very much worth watching) featured a murder in an oxygen chamber in which the victim is given a comb that would cause static electricity. Apparently based on a real and tragic incident: Schenectady Gazette - Google News Archive Search

 

[formernuke]

O2 is not flammable. It does make existing fires hotter and bigger though.

So in your case the flame from the lighter will be bigger and hotter. In order to get a boom you need more actual fuel, a lot more.

 

[Akimbo]

I went to an U/W explosives school with a company called Brower...

I was on a project with Brower off the Carolinas looking for a wreck. We had a target but needed to move a lot of sand to identify it so we lit off 55 gallon drums of one of their liquid formulations. It looked like one of those WWII drum depth charges going off from about a mile away.